Chess databases as a research vehicle in psychology : modeling large data

The game of chess has often been used for psychological investigations, particularly in cognitive science. The clear-cut rules and well-defined environment of chess provide a model for investigations of basic cognitive processes, such as perception, memory, and problem solving, while the precise rating system for the measurement of skill has enabled investigations of individual differences and expertise-related effects. In the present study, we focus on another appealing feature of chess—namely, the large archive databases associated with the game. The German national chess database presented in this study represents a fruitful ground for the investigation of multiple longitudinal research questions, since it collects the data of over 130,000 players and spans over 25 years. The German chess database collects the data of all players, including hobby players, and all tournaments played. This results in a rich and complete collection of the skill, age, and activity of the whole population of chess players in Germany. The database therefore complements the commonly used expertise approach in cognitive science by opening up new possibilities for the investigation of multiple factors that underlie expertise and skill acquisition. Since large datasets are not common in psychology, their introduction also raises the question of optimal and efficient statistical analysis. We offer the database for download and illustrate how it can be used by providing concrete examples and a step-by-step tutorial using different statistical analyses on a range of topics, including skill development over the lifetime, birth cohort effects, effects of activity and inactivity on skill, and gender differences

Square-pyramidal copper (II) complexes of linear tetradentate edda-type ligands forming six-membered rings. Molecular structures of [Cu(1,3-pdda) (H2O)] and [Cu(eddp) (H2O)] · 3.5H2O

Three square-pyramidal copper(II) complexes containing a linear O-N-N-O-type tetradentate ligand have been prepared and characterized. The ligands used are 1,3-propanediamine-N,N′-diacetate ion (1,3-pdda), ethylenediamine-N,N′-di-3-propionate ion (eddp) and 1,3-propanediamine-N,N′-di-3-propionate ion (1,3-pddp). In the three compounds a water molecule is in the axial position while the four atoms of ligand are in the basal plane. A five-coordinate, square-pyramidal geometry has been established crystallographically for the complexes [Cu(1,3-pdda)(H2O)] (1) (orthorhombic, Pnma, a = 8.937(4), b = 11.770(5), c = 10.269(5) Å3, V = 1080.2(8) Å3, Z = 4 and R = 0.0699) and [Cu(eddp)(H2O)] · 3.5H2O(2) (monoclinic, C2/c, a = 24.430(8), b = 12.195(3), c = 10.514(2) Å, β = 110.92(2) V = 2926(1) Å3, Z = 8 and R = 0.0515). The Cu(II) ions of these structures are lifted out of plane of the four in-plane ligand atoms by distances ρ = 0.182(5) and 0.154(1) Å, respectively. The six-membered diamine ring of complex 1 assumes the stable chair conformation. The other rings of chelates have expected conformations. The structural data correlating the square-pyramidal stereochemistry are discussed in relation to those obtained for similar complexes. The IR and electronic absorption spectra of [Cu(edda-type) (H2O)] complexes are discussed in comparison with those of related complexes of known geometries. The magnetic measurements are also reported for the complexes studied. © 1998 Elsevier Science S.A

Study of the reactions of hexanitrocobaltates(III) with amino acids. II. Determination of the configuration of dinitrobis(glycinato)cobaltate(III) ions

In a previously published paper1 we have undertaken a study of the reactions of hexanitrocobaltate(III) with amino acids. The first reaction we studied was that of glycine with potassium and sodium hexanitrocobaltate( III). In such a way the synthesis of a new class of complex compounds, dinitrobis (glycinato)- cobaltates(III) (MI[Co(H2NCH2COO)2(N02)2]), was given

Study of the reaction of hexanitrocobaltates(III) with amino acids. IV. The reations with DL-alanine, D-alanine, L-alanine, and β-alanine

The reactions of alkali hexanitrocobaltates(III) with DL-alanine, D-alanine, L-alanine, and β-alanine have been investigated. Thereby new classes of alkali dinitro-bis (aminoacido)cobaltates(III), M[CoAm2(NO2)2] were obtained. It was established that the products obtained contain two nitro groups in the cis position

Study of the reactions of hexanitrocobaltates(III) with amino acids. VII. Geometrical isomerism and absolute configuration of dinitrobis(aminoacidato)cobaltate(III) ions

Dinitrobis(aminoacidato)cobaltate(III) salts with L-α-aminobutyric acid, aminoisobutyric acid, L-valine, L-norvaline, L-leucine, L-norleucine, and L-isoleucine were prepared and resolved into optical isomers. We report their electronic absorption, circular dichroism and infra-red spectra, and some PMR spectra. The date confirm our earlier assumption of the geometrical isomerism and absolute configuration of analogous ions with glycine, alanine, and β-alanine. The only geometrical isomer found in our preparations is the cis dinitro complex with amino groups trans. The (+)589-optical isomers are assigned the P(C2) absolute configuration

Preparation, characterization and X-ray analysis of [Co-2(Cl)(2)tpmc](BF4)(2). Comparative structural analysis with the complexes having analogous geometries and ligands

A novel binuclear Co(II) complex, [Co-2(Cl)(2)tpmc](BF4)(2) (tpmc=N,N,N",N"'-tetrakis(2-pyridylmethyl)-1,4,8,11-tetraazacyclotetradecane), was prepared and structurally characterized by X-ray diffraction analysis at low temperature. The complex crystallizes in P2(1)/c space group of the monoclinic crystal system, and its crystals are isomorphic with those Of [Cu-2(Br)(2)tpmc](ClO4)(2) complex. In the crystal structure the complex cations [Co-2(Cl)(2)tpmc](2+) are settled around the inversion centres. Cobalt(II) is exo coordinated with four macrocyclic N atoms, and Cl- supplements the fifth coordination site. Based on the index of trigonality, the coordination polyhedron formed around Co(II) ion is described as distorted trigonal bipyramid. Two metal centres are at a distance of 5.710 angstrom. This is the first Co(II) complex for which X-ray analysis confirmed a chair conformation of tpmc ligand. IR, EPR (X-band) and UV/VIS absorption and reflectance spectra, molar conductivities and magnetic measurements (SQUID) are used to study the investigated complex. A comparative structural analysis with some of the described Co(II) and Cu(II) complexes of analogous geometries and type of pendant azamacrocyclic ligands was also done

X-ray analyses, spectroscopic and magnetic properties of [Cu4(succinato)(tpmc)2](ClO4) 6·2C2H5OH·4H2O and [Cu2(C6H5COO)tpmc](ClO4) 3·0.5CH3OH·0.5H2O complexes

[Cu4(succinato)(tpmc)2](ClO4) 6 · 2H2O (tpmc = N,N′,N″,N‴-tetrakis-(2-pyridylmethyl)-1,4,8,11-tetraa zacyclotetradecane, succinato = dianion of succinic acid) has been prepared and characterized by elemental analysis, UV/vis, IR, EPR (X-band) spectra, conductivity and magnetization measurements (SQUID). Based on a low-temperature measurements (100(2) K), X-ray analyses of the first tetranuclear Cu(II)-tpmc complex, single crystal of which corresponded to the [Cu4(succinato)(tpmc)2](ClO4) 6·2C2H5OH·4H2O (1) and of the previously described [Cu2(C6H5COO)tpmc](ClO4) 3·0.5CH3OH·0.5H2O (2) were also done. The complexes crystallize in triclinic P over(1, ̄) (1) and monoclinic P21/c (2) space groups. The geometry around the first Cu(II) coordination sphere in the tetranuclear complex (1) is almost regular square-based pyramidal, while significant distortion around the other metallic center was observed. The angular structural parameter (τ), which is applicable to five coordinate structures as an index of degree of trigonality, was found to be 0.05 and 0.40, respectively. In the binuclear complex (2) the geometry around the first Cu(II) coordination sphere is regular square-based pyramidal (τ = 0.09), while around the other is distorted trigonal bipyramidal (τ = 0.79). In complexes (1) and (2) the bridging carboxylate groups are coordinated to metallic centres in a syn-anti mode. Weak ferromagnetic interactions are observed between copper(II) ions, connected through syn-anti monocarboxylate bridges (2J = +1.26 and +1.84 cm-1 in complexes (1) and (2), respectively). Additional antiferromagnetic interaction through succinato anion (zJ′ = -1.57 cm-1) gives finally rise to antiferromagnetic interactions, observed in magnetic measurements in tetrameric complex (1)